Systems and methods of comparative computed tomography (CT) for qualification of commercial grade items

ABSTRACT

A method of qualifying physical components using computed tomography (CT) includes obtaining qualified CT data from a CT scanner for at least one qualified physical component. Qualification data is generated based on the qualified CT data, where the qualification data defines a qualification envelope. Candidate CT data is obtained from the CT scanner for a candidate physical component. Comparison data is then generated based on the candidate CT data and the qualification data, where the comparison data indicates whether the candidate CT data is within the qualification envelope defined by the qualification data. An acceptance signal is generated if the comparison data meets acceptance criteria.

CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY CLAIM

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/584,846 filed Nov. 12, 2017 and entitled “Use of comparativecomputed tomography (CT) for qualification of commercial grade items,”which is incorporated by reference into this application in its entirety

FIELD

The disclosure is directed to the field of single-energy and dual-energyComputed Tomography (CT). More specifically, the disclosure is directedto using to single-energy and dual-energy CT for industrial inspectionand qualification.

BACKGROUND

Traditionally, industrial CT scanning is used for non-destructiveexamination (NDE). In the past, CT scanning was used to examine theinternal configuration and condition of nuclear power plant componentsand their internal parts. This work was performed on behalf of nuclearutilities and other industries requiring high-reliability. For example,traditional CT scanning was performed to identify condition andconfiguration of power plant components and to attempt to identifyinternal non-metallic parts within sealed components.

Many highly regulated, technical industries require an enhanced degreeof reliability for the component parts that are integrated into thedevices and/or systems that operate within those industries. Thisreliability requirement is taken very seriously because a part,component or system failure could result in loss of life or asignificant risk to the health and safety of employees and the public.Typically, item quality (and its reliability) is ensured by establishingdetailed specifications representing the item design requirements andthrough implementation of very rigorous Quality Assurance and QualityControl (QA/QC) Programs. This approach has been effective at producingvery reliable parts, components and systems, however, it comes with thedown-side of being slow, costly and requiring extensive documentation.In addition, it results in a limitation on the number of suppliers whocan meet all of the requirements to produce a qualified item.

For the industries that require a specially qualified inventory of spareparts, manufactured and tested to the requirements of technicalspecifications and an approved quality program, there is typically along lead time required to acquire those parts. This causes the users tomaintain an extensive, on-hand, qualified, inventory to meet operationalneeds.

SUMMARY

This disclosure describes a rigorous comparative CT process that willprovide physical component qualification equivalent to components moretraditionally qualified by technical specification, testing andimplementation of quality program requirements. The disclosure relatesto using CT to scan a representative sample of the existing, alreadyaccepted inventory of qualified items to obtain dimensional andmaterials information from those items. The electronic files from thosescans will be used to identify a range of dimensional acceptability inall orientations, and the identification of the material (or materials)that the item is made of.

The scan data from representative samples will be used to constructelectronic baseline files for each class of items. These baseline filesare used similarly to a mechanical go/no-go gage for qualifyingcomponents, as will be understood by those skilled in the art. Oncethese go/no-go baseline files are prepared, subsequent commercial gradeitems can be CT scanned and their dimensional and materials data can becompared to the established go/no-go baseline. If it can be confirmedthat scan data from a subsequent item meets the requirements of thesample baseline, that item can be designated as equivalent to thepreviously scanned baseline items that were procured to the requirementsof the quality program and in compliance to the item's specification.The subsequent scanned items can then be used for the same applicationsas the qualified baseline. The electronic CT scan record, comparing tothe already qualified baseline, provides the assurance of subsequentitem quality and reliability.

In one example, the system for qualifying physical components using CTwill include 1) a CT scanner; 2) a jig for positioning the physicalcomponent on the CT scanner; 3) a processor operatively connected to theCT scanner; and 4) non-transient memory, operatively connected to theprocessor, that includes instructions for comparing thethree-dimensional and materials CT scan information for the purpose ofdetermining likeness.

In one example, the CT scan comparison is accomplished by 1) performinga CT scan of at least one qualified physical component; 2) establishinga qualification envelope from the scan data of the already qualifiedphysical component: 3) performing a CT scan for a candidate physicalcomponent; 4) comparing data based on the candidate CT data and thequalification data to determine whether the candidate CT data is withinthe qualification envelope defined by the qualification data; and 5)generating an acceptance signal if the comparison data meets acceptancecriteria.

In an example, the qualification envelope may be influenced by: 1) theaccuracy of positioning the physical component in the CT scanner; 2) theresolution and repeatability of the CT scanner and CT data; 3) a degreeof conservatism assigned to meet qualification process requirements ofthe candidate physical component's end user; and 4) generating anordered list and eliminating a subset of the ordered list of recordedmeasurements from the plurality of components for each volumetric pixel(voxel). In an example, the subset eliminated may be based on aconservatism factor.

In an example, an acceptance criteria for determining likeness of thecandidate physical component to the qualified physical component(s) mayrequire that every voxel of the candidate CT data is within thequalification envelope defined for that voxel by the qualification datawhere: 1) the qualified CT data includes a plurality of volumetricpixels (voxels); 2) the qualification data includes a plurality ofvoxels; 3) candidate CT data includes a plurality of voxels; and 4) thecomparison data includes a plurality of voxels. Each voxel includesthree-dimensional (3D) location and material information. The materialinformation may include density information based on radiopacity, andeffective-atomic number (Z_(eff)) derived from scanning at multipleenergy levels.

Throughout this application, the terms “parts” and “components” are usedto refer to the items that are being scanned. Simple components may onlybe comprised of a single part. More complex components are typicallycomprised of many parts.

Throughout this application, the term “commercial grade” is used torefer to items that are generally available to the commercial market.They may or may not be manufactured to rigorous specifications orquality programs requirements.

Throughout this application, the term “qualified” is used to refer tospecial application items which are manufactured to rigorousspecifications or quality programs requirements. It also refers to theprocess of providing an equivalent level of item technical adequacy andquality assurance that is ensured through this process of comparativeCT.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an example of the disclosed CT systemillustrating its basic components and the relationships between them, inaccordance with the present disclosure.

FIG. 2 is a flow chart illustrating an example process for qualifyingcommercial-grade components for use in applications requiringqualified-grade components.

FIG. 3 is a flow chart illustrating an example process for generatingqualification data, in accordance with the present disclosure.

FIG. 4 is a flow chart illustrating an example process for evaluating acandidate component against qualification data, in accordance with thepresent disclosure.

FIG. 5 is a flow chart illustrating an example process for evaluationthe comparison data file for acceptance or rejection.

FIG. 6 is an isometric visualization of a CT-scanned baseline-qualifiedcomponent file that will be generated by CT scanning, in accordance withthe present disclosure. FIG. 6A is a visualization of a 2D cross-sectionof the CT-scanned baseline-qualified component file from FIG. 6, inaccordance with the present disclosure. FIG. 6B is a detailedvisualization of a portion of the 2D cross-section of the CT-scannedbaseline-qualified component file from FIG. 6A, illustrating individualvoxels, in accordance with the present disclosure

FIG. 7 is an isometric visualization of a range of dimensional andmaterial properties from the combined data representing multipleCT-scans of baseline qualified components, in accordance with thepresent disclosure. FIG. 7A is a visualization of a 2D cross-section ofthe range of dimensional and material properties from the combined datarepresenting multiple CT-scans from FIG. 7, in accordance with thepresent disclosure.

FIG. 8 is an isometric visualization of a conservative digitalqualification data file, superimposed onto the actual measured range ofbaseline component properties. This figure illustrates a reduced rangeof components properties that may be used to establish qualification ofeach individual commercial grade part by documenting that it isconservatively bounded by the known properties of the baseline parts, inaccordance with the present disclosure. FIG. 8A is a visualization of a2D cross-section of the conservative digital qualification data file,superimposed onto the actual measured range of baseline componentproperties.

FIG. 9 is a cross-section view of a visualization of a CT-scannedcandidate component superimposed on the digital qualification dataillustrating failing properties of the candidate component compared tothe qualification data, in accordance with the present disclosure.

FIG. 10 is a cross-section view of a visualization of a CT-scannedcandidate component superimposed on the digital qualification dataillustrating passing properties of the candidate component compared tothe qualification data, in accordance with the present disclosure.

FIG. 11 is an isometric view of a visualization of a CT-scannedcandidate component superimposed on the digital qualification dataillustrating failing properties according to the qualification data, inaccordance with the present disclosure.

FIG. 12 is an isometric view of a visualization of a CT-scannedcandidate component superimposed on the digital qualification dataillustrating passing properties according to the qualification data, inaccordance with the present disclosure.

Although the above drawings are provided to provide a conceptualrepresentation of the CT scanned part and its evaluation against thequalification data, this process does NOT require generation of a visualrepresentation of the part, or of the qualification data developed fromthe sampling of qualified parts. The comparison of the commercial gradeitems to the qualified baseline parts of the qualification data is madeusing the electronic files developed from the CT scans, in accordancewith the present disclosure.

Detailed dimensional and materials properties of a particular portion orsub-part of a component to be qualified can be extracted from the CTscan data if an investigation of an out-of-tolerance criteria isdesired, however, this process is intended primarily for a productionline type acceptance/rejection decision on qualification of commercialgrade parts for qualified applications, in accordance with the presentdisclosure.

DETAILED DESCRIPTION

Any example description of x-ray CT scanning equipment or CT scanningprocesses included with this disclosure are for general informationpurposes only, since the actual equipment and processes used will beselected to optimize their effectiveness for the composition andcomplexity of the items subjected to this comparative CT process.

This method of comparative CT scanning is intended to result in aACCEPT/REJECT DECISION for qualification of commercial grade items to beused in applications requiring qualified components. Additional methodsteps may be performed to resolve the reason a part was rejected.However, such an effort complicates the process, increases costs andreduces its efficiency. Having faster access to qualified, replacementparts is expected to result in a need for smaller inventories.Commercial suppliers that were not previously suppliers to the highlyregulated industries will be able to prove their product(s) can bedocumented as being fit for qualified applications. The electroniccomparison CT files will provide a comprehensive record of productquality. CT-qualified parts and components are expected to be lesscostly than the traditionally-qualified versions, even with the cost ofthe CT-qualification added to the commercial item cost.

Likely Users:

Likely users are industries that require high reliability and rigorousquality standards for their spare parts and components—particularlyindustries where operational safety is extremely important to theproduct users, facility staff and local community. Examples include:

-   -   Commercial Nuclear Power    -   Commercial Aviation    -   Military Equipment (Aviation, Naval, Ground)    -   Space (Communications, Exploration, Manned)    -   Medical Devices    -   Pharmaceuticals Processing    -   Hazardous Waste (Radioactive/Chemical/Biological)    -   Safety Equipment (Fire Protection/Explosive/High        Pressure/Electrical)    -   Other highly regulated industries

The industrial CT, used in this disclosure as the mechanism to establishlikeness of commercial grade and qualified parts, is a next steprefinement beyond x-ray, digital radiography used to performtwo-dimensionally, visual examinations of components or items. Thetwo-dimensional projection provides images that include artifacts frommaterials around the plane of interest. CT scans use many radiographicprojections at different angles to lessen this ambiguity. The CT scannergenerates a series of two-dimensional (2D) “slices” of a scanned objectfrom multiple angles and, normally, multiple elevations. The CT softwarethen reconstructs these “slices” to produces a mathematically accurate3D reconstruction of a physical component that can be examined onvarious planes. The 3D reconstruction includes an array of data pointsrepresenting volumetric pixels (voxel). Just as a 2D image is made froma map of pixels, where each pixel defines a 2D location and a color,each voxel in the 3D reconstruction created by the CT defines a 3Dposition and material information for that location.

Because this disclosure relates to comparing CT scan data fromcomponents being evaluated for likeness, a reliable and consistentcalibration of the CT scanner is essential. Control of the scanningprocess, scan repeatability, and the accuracy of the calibrationstandards are all important to ensuring a valid comparison of CT scandata.

A wide variety of CT scanner configurations and source/detectorcombinations are available for getting the best possible results fromscans of a wide variety of physical components. Selection of anoptimized scanner considers the size and density of the item beingscanned, ability to achieve adequate resolution and to addressmanufacturing tolerances, and being able to distinguish between multiplematerials in the scan.

Dual-energy scanning, at low energy (20-200 keV) or high energy (2-9MeV) can be used to calculate effective-atomic number (Z_(eff)) ofmaterial being scanned. The two energy levels chosen is often a functionof the available CT scanner source and detector. In both low and highenergy applications, the basis for measurement of the materialcomposition comes from changes in the relative proportions of thedifferent attenuation mechanisms, which constitute the total attenuationof the physical component.

Referring now to the Figures, in which like reference numerals representlike parts, various embodiments of the computing devices and methodswill be disclosed in detail. FIG. 1 is a block diagram illustrating oneexample of a CT scanning system 100 suitable for use in generating,comparing and, when necessary, visualizing x-ray scan data.

FIG. 1 illustrates a representative x-ray scanning system 100 that maybe used to implement the teachings of the instant disclosure. The system100 may be used to implement, for example, one or more steps of themethod illustrated in FIGS. 2-5, as described in greater detail below.The system 100 includes one or more processors 102 operatively connectedto a storage component 104. The storage component 104, in turn, includesstored executable instructions 116 and data 118. In an embodiment, theprocessor(s) 102 may include one or more of a microprocessor,microcontroller, digital signal processor, co-processor or the like orcombinations thereof capable of executing the stored instructions 116and operating upon the stored data 118. Likewise, the storage component104 may include one or more devices such as volatile or nonvolatilememory including but not limited to random access memory (RAM) or readonly memory (ROM). Further still, the storage component 104 may beembodied in a variety of forms, such as a hard drive, optical discdrive, floppy disc drive, flash memory, etc. Processor and storagearrangements of the types illustrated in FIG. 1 are well known to thosehaving ordinary skill in the art. In one embodiment, the processingtechniques described herein are implemented as a combination ofexecutable instructions and data within the storage component 104.

As shown, the scanning system 100 may include one or more user inputdevices 106, a display 108, a peripheral interface 110, other outputdevices 112, and a network interface 114 in communication with theprocessor(s) 102. The user interface 106 may include any mechanism forproviding user input to the processor(s) 102. For example, the userinterface 106 may include a keyboard, a mouse, a touch screen,microphone and suitable voice recognition application, or any othermeans whereby a user of the system 100 may provide input data to theprocessor(s) 102. The display 108 may include any conventional displaymechanism such as a cathode ray tube (CRT), flat panel display,projector, or any other display mechanism known to those having ordinaryskill in the art. In an embodiment, the display 108, in conjunction withsuitable stored instructions 116, may be used to implement a graphicaluser interface. Implementation of a graphical user interface in thismanner is well known to those having ordinary skill in the art. Theperipheral interface 110 may include the hardware, firmware and/orsoftware necessary for communication with various peripheral devices,such as media drives (e.g., magnetic disk, solid state, or optical diskdrives), other processing devices, or any other input source used inconnection with the instant techniques. For example, the peripheralinterface may be a Universal Serial Bus (USB). Likewise, the otheroutput device(s) 112 may optionally include similar media drivemechanisms, other processing devices, or other output destinationscapable of providing information to a user of the device 100, such asspeakers, LEDs, tactile outputs, etc. Finally, the network interface 114may include hardware, firmware, and/or software that allows theprocessor(s) 102 to communicate with other devices via wired or wirelessnetworks, whether local or wide area, private or public, as known in theart. For example, such networks may include the World Wide Web orInternet, or private enterprise networks, as known in the art.

The scanning system also includes a CT scanner 130 which is connected tothe processor(s), 102 for example via the network interface 114 and/orthe peripheral interface 110. The CT scanner 130 includes an X-raysource 132. The X-ray source 132 projects X-ray 134 which pass through ascanned sample 136 and are detected by X-ray detectors 138, as will beunderstood by those skilled in the art. A number of different X-raysource types and arrangements, X-ray detection devices and arrangements,and sample support arrangements are known to those skilled in the artand can be used in conjunction with the systems and methods described inthis disclosure

While the scanning system 100 has been described as one form forimplementing the techniques described herein, those having ordinaryskill in the art will appreciate that other, functionally equivalenttechniques may be employed. For example, as known in the art, some orall of the functionality implemented via executable instructions mayalso be implemented using firmware and/or hardware devices such asapplication specific integrated circuits (ASICs), programmable logicarrays, state machines, etc. Furthermore, other implementations of thesystem 100 may include a greater or lesser number of components thanthose illustrated. Once again, those of ordinary skill in the art willappreciate the wide number of variations that may be used is thismanner. Further still, although a single scanning system 100 isillustrated in FIG. 1, it is understood that a combination of suchcomputing devices may be configured to operate in conjunction (forexample, using known networking techniques) to implement the teachingsof the instant disclosure.

FIG. 2 illustrates an example process 200 for qualifyingcommercial-grade components for use in applications requiringqualified-grade components. Process 200 includes generatingqualification data 300 based on one or more pre-qualified physicalcomponents, generating comparison data 400, and evaluating thecomparison data 500. These steps are illustrated in greater detail inFIGS. 3-5. FIG. 3 illustrates an example process 300 for generatingqualification data based on one or more pre-qualified physicalcomponents. At 302 a required number of qualified sample components tobe scanned is determined. The number of samples may be determined by anappropriate statistical method based on the precision and confidenceinterval required for the final application. For example, commercialnuclear applications may use the guidance of NCIG-09, SelectiveInspection Process (incorporated by reference) to determine appropriatesample sizes. Other application may use similar methods prescribed bythe industry or government regulations.

At 304 a qualified physical component is scanned using the CT scanner.As discussed above the scanner will generate qualified CT data, which isa digital file including an array of voxels. The information for eachvoxel describes its three-dimensional position relative to the othervoxels and material information. When the CT scan is conducted at asingle energy level (e.g. 20 keV) the material information will includeonly density information. If the CT scan is conducted at multiple energylevels, the material information will also include a calculatedeffective atomic number, Z_(eff).

At 306, one or more datums may be identified in the qualified CT data.The datums can be used later to align the qualified data for multiplescans of qualified physical components to generate the finalqualification data. Datums may help to ensure that each voxel in eachscan is aligned as closely as possible with the corresponding voxel inother scans.

The types of datums and the methods for establishing them may bedetermined by the nature of the physical components and precisionrequired by the application. In the simplest example, a datum may bemerely a predetermine voxel within the array, which is essentially apoint datum determined by the physical characteristics of the scanner.This could represent a point at the center of the detector space withinthe scanner or at an extreme edge of the detector space, for example thesample table. A slightly more sophisticated approach may introduce aradiopaque of known geometry and a know position within the detectionspace to define a datum or datums. For example, a radiopaque cylindercould be fixed vertically to the sample table to establish a verticaldatum axis and a datum plane associate with the surface of the table.Similarly, a radiopaque cube could be fixed to the surface of the sampletable to establish a system of orthogonal planes suitable for aCartesian coordinate system.

In all of the examples above, consistent placement of the physicalcomponent relative to the datum(s) will be essential to accuratelyaligning the digital files for each scan. Consistent placement of thephysical component can be enhanced by introducing fixtures to thescanner to hold the physical component consistently. In one example, thefixture may be present in the scanner during calibration, in which casethe fixture will not appear within the digital file for a particularscan based on that calibration. In another example, the fixture may beintroduced after calibration and would show up in the digital file. Thismay be desirable if the fixture is to be used to determine datums. Inanother example, a hybrid approach may be used, where the bulk of thefixture is present during calibration, but certain radiopaque elementsare added for actual scans to assist in defining datums.

In another example, datums may be determined using the geometry of thephysical components themselves. For example, if a component iscylindrical, the software could identify the cylinder and define anouter diameter, inner diameter, or axis as a datum. In one example, thesoftware could used edge-detection techniques from machine-vision orcharacter-recognition techniques to mathematically determine theboundaries of known geometric features within the component. Thesefeatures could then be used to generate datums.

At 308 the software checks if the required number of scans of qualifiedphysical components has been completed. At 310, the datums determinedfor each digital file are used to align the voxels in each file.

At 312 the X-ray scan data is evaluated for each voxel to determine thematerial data (density and/or effective atomic number, Z_(eff)), foreach voxel in each scan. At 314 the material data for each voxel is thenstructured in an array. For example, density or Z_(eff) data may bestructured from highest to lowest. For example, see Table 1, below,where the left-hand column represents density data for a particularvoxel in the order the readings were recorded. The center columnrepresents the density information structured from highest to lowestdensity.

At 316 a conservatism factor is applied to the structured material datato determine a qualification envelope for each particular voxel. In thesimplest example, the conservatism factor may apply a linear restrictionto eliminate outliers. This example is illustrated in right-hand columnTable 1. In this example, a linear 80% conservatism factor is employed,so the lowest 10% and highest 10% of density readings are eliminated.The upper and lower bounds of the remaining density reading representthe qualification envelope. Thus, any density reading between 0.0121g/cm³ and 7.85 g/cm³ would be acceptable. This type of density profilemay exist for voxels close to an edge of the physical component. Voxelsalways in the body of the part would have similar densities for everyscan. Similarly, voxels always outside of the component would haveconsistently low densities (i.e. the density of air).

TABLE 1 Voxel Density Reading g/cm³ Initial Structured QualificationEnvelope 7.81 7.91 7.79 7.85 7.85 .00123 7.84 7.84 7.85 7.81 7.81 .001007.80 7.80 7.78 7.79 7.79 7.91 7.78 7.78 .00121 .00123 .00123 7.80 .00121.00121 7.84 .00100

Other approaches for applying a conservatism factor can also be applied.In one example, if the number of scans does not lend itself to a neatapplication of linear conservatism factor, linear extrapolation could beused. For example, if a conservatism factor of 90% was applied to thedata in Table 1 instead of 80%, the number of data points would beinappropriate. Instead, the qualification envelope could be linearlyinterpolated between the two highest and lowest density readings. Usingthe data in Table 1, a 90% conservatism factor would “land” halfwaybetween the two highest and lowest density readings, so the linearlyinterpolated qualification envelope would be 0.00111 to 7.88 g/cm³.Statistical methods could also be used. For example, the conservatismfactor could be ±2 standard deviations, or a fixed ratio of the mean ormedian density measurement. All of the above techniques could also beapplied to the effective atomic number.

FIG. 4 illustrates an example process 400 for evaluating a candidatecomponent against qualification data generated according to FIG. 3. At402 the physical component to be qualified—the candidate physicalcomponent—is scanned by the same CT scanner as the qualified components.The setup should be the same as what was used to scan the qualifiedcomponents. This includes calibration, component placement and/orfixturing, and scanning energies.

In another example, different scanners may be used to scan the candidatecomponents versus the qualified components. Multiple scanners could evenbe used to scan the qualified components. In this situation additionaltechniques would be required to remove artifacts particular to eachscanner, as known to those skilled in the art. When a single scanner isused for all of the scans, the consistent artifacts peculiar to themachine will cancel themselves out when generating the qualificationdata and comparison data. This will not be the case if multiple scannersre used, for example when the scanners are separated by hundreds ofmiles. In these situations, the scanning artifacts must be removed for avalid comparison.

At 404 appropriate datums are identified in candidate part scan data tocorrespond to the datums in the qualified CT data and the qualificationdata. At 406 the datums in the candidate CT data are aligned with thedatums in the qualification data.

At 408 the candidate CT data is evaluated against the qualification dataon a voxel-by-voxel basis. At 410 the material data for the voxel in thecandidate CT data is compared to the qualification envelope for thecorresponding voxel in the qualification data to generate a comparisondata file. At 412 the voxel being evaluated is recorded as rejected ifthe material data for the candidate voxel is not within thequalification envelope. At 414 the voxel being evaluated is recorded asaccepted if the material data for the candidate voxel is within thequalification envelope. At 416 the comparison data file is evaluated toconfirm that all of the voxels have been evaluated. If all of the voxelshave been evaluated, the comparison data file is ready for evaluation.

FIG. 5 illustrates an example process for evaluating the comparison datafile for acceptance or rejection. At 502 the acceptance criteria isobtained. In one example, the acceptance criteria simply requires thatthe 100% of the voxels in the comparison data be accepted. In anotherexample, the acceptance criteria may be a fixed percentage less than100%. In another example, the percentage of voxels that must be acceptedmay depend on where they are located. For example, voxels in an area ofthe component know to be critical may require 100% acceptance whilevoxels outside the critical area may not require 100% acceptance. Thismay allow some forgiveness for potential errors in non-critical areas.Conversely, a lower acceptance percentage may be accepted in regions ofthe component known to have variable interfaces between sub-components.At 504 the comparison data file is evaluated to determine if theacceptance criteria is met. At 506 a rejection report is generated ifthe acceptance criteria is not met. At 508 an acceptance report isgenerated if the acceptance criteria is met.

FIG. 6 is an isometric visualization of a CT-scanned baseline-qualifiedcomponent file 601 that might be generated by CT scanning. Forillustration purposes, the baseline-qualified component file 601represents a cube-shaped lattice of supports.

FIG. 6A is a visualization of a 2D cross-section of the CT-scannedbaseline-qualified component file from FIG. 6. Because of thelattice-like structure of the baseline-qualified component file 601, thecross-section appears similar to a plan view of file 601.

FIG. 6B is a detailed visualization of a portion of the 2D cross-sectionof the CT-scanned baseline-qualified component file from FIG. 6A,illustrating individual voxels. The black squares 602 represent voxelsthat include solid material in every scan. The gray squares 603, 604represent voxels where some scans indicate solid material and otherscans indicated air. Depending on the resolution of the scan andaccuracy of the part placement and datums, this may represent and edgecondition 603 or a void 604 in one of the scanned parts. The square at605, and the other white space, represent voxels which always indicatesan absence of solid material.

FIG. 7 is an isometric visualization of a range of dimensional andmaterial properties from the combined data representing multipleCT-scans of baseline qualified components. The originalbaseline-qualified component file 601 is shown. Additional scans, forexample of additional qualified components and/or re-scans for the samecomponent result in a maximum material boundary 702 and a minimummaterial boundary 704.

FIG. 7A is a visualization of a 2D cross-section of the range ofdimensional and material properties from the combined data representingmultiple CT-scans from FIG. 7.

FIG. 8 is an isometric visualization of a conservative digitalqualification data file, superimposed onto the actual measured range ofbaseline component properties. This figure illustrates a reduced rangeof components properties that may be used to establish qualification ofeach individual commercial grade part by documenting that it isconservatively bounded by the known properties of the baseline parts.The maximum material boundary 702 and a minimum material boundary 704are again illustrated. The boundaries of the qualification data file 800are also illustrated. These boundaries represent the application of theconservatism factor to the original maximum material boundary 702 and aminimum material boundary 704.

FIG. 8A is a visualization of a 2D cross-section of the conservativedigital qualification data file, superimposed onto the actual measuredrange of baseline component properties.

FIG. 9 is a cross-section view of a visualization of a CT-scannedcandidate component superimposed on the digital qualification dataillustrating failing properties of the candidate component compared tothe qualification data. The failing section 902 of the failing candidatecomponent 900 is highlighted relative to the boundaries of thequalification data file 800.

FIG. 10 is a cross-section view of a visualization of a CT-scannedcandidate component superimposed on the digital qualification dataillustrating passing properties of the candidate component compared tothe qualification data. As illustrated in the figure, the passingcandidate component 1000 is entirely within the boundaries of thequalification data file 800.

FIG. 11 is an isometric view of the failing component 900 and theboundaries of the qualification data file 800. FIG. 12 is an isometricview of the passing component 1000 and the boundaries of thequalification data file 800.

Process Control

The comparative CT scanning process for determining that candidatephysical components are like their traditionally qualified physicalcomponents must be controlled by a rigorous quality program, equivalentto that used for the traditional qualification of physical components.Control of the comparative CT process ensures that the comparative CTprocess gets consistent and repeatable results, and that the commercialgrade item that has been qualified by comparative CT has the same levelof assurance that it will be equivalent to the traditionally qualifiedphysical component in fit and performance of its design function.

Controlled procedures for performing the scans must be prepared,reviewed and approved in accordance with a quality assurance programbased on the same requirements as that used for the traditionallydesigned and manufactured physical components. Procedures must bespecific to the CT scanners used and they are to be updated to addressany physical chances to the CT scanner or to how it is operated.

Calibration of scanning equipment must be performed per the requirementsof the CT scanner manufacturer in order to ensure the equipmentperformance necessary for the comparative CT process. Controlledprocedures must be used for performance of the CT scanner calibrations.Records of calibrations performed must be maintained.

Equipment operating software used for CT scanning is typically providedby the manufacturer of the CT scanning equipment. Requirements forqualification of the CT scanner software is based upon the requirementsof the quality program applied to the particular comparative CT scanningapplication. If the CT scanner software has been modified by the CTscanner owner, those same quality program requirements must be appliedto the modified software.

As is the case for the equipment operating software, requirements forpurpose-specific software used to establish the go/no-go baseline isbased upon the requirements of the quality program applied to theparticular comparative CT scanning application. If the go/no-go baselinesoftware is subsequently modified, those same quality programrequirements must be applied to the modified software.

Qualifications of CT scanner operators and scan data interpreters mustbe established and maintained per controlled procedures. For the CTscanner operators, records of associated scanner operations trainingand/or trial scan demonstrations will ensure that the operators arefamiliar with the proper operation of the specific types of equipmentused for the CT scans. For the CT scan data interpreters, records ofassociated data interpretation training and/or trial data interpretationdemonstrations will ensure that the scan data interpreters are familiarwith the proper interpretation of the scan results from the specific CTscanners used and their associated software.

The baseline and comparison CT item records are quality records thatdocument that the physical component is qualified. Controlled proceduresdescribe record format and method of maintaining the comparative CT scanrecords. The records must be recoverable at any time during the timethat the component is in inventory or in service. If comparative CTrecords are destroyed or otherwise unrecoverable, then the component isno longer considered qualified and it must be removed from service orinventory.

To facilitate an understanding of the principals and features of thedisclosed technology, illustrative embodiments are explained below. Thecomponents described hereinafter as making up various elements of thedisclosed technology are intended to be illustrative and notrestrictive. Many suitable components that would perform the same orsimilar functions as components described herein are intended to beembraced within the scope of the disclosed electronic devices andmethods. Such other components not described herein may include, but arenot limited to, for example, components developed after development ofthe disclosed technology.

It must also be noted that, as used in the specification and theappended claims, the singular forms “a,” “an” and “the” include pluralreferents unless the context clearly dictates otherwise.

By “comprising” or “containing” or “including” is meant that at leastthe named compound, element, particle, or method step is present in thecomposition or article or method, but does not exclude the presence ofother components or method steps, even if the other such compounds,material, particles, method steps have the same function as what isnamed.

It is also to be understood that the mention of one or more method stepsdoes not preclude the presence of additional method steps or interveningmethod steps between those steps expressly identified. Similarly, it isalso to be understood that the mention of one or more components in adevice or system does not preclude the presence of additional componentsor intervening components between those components expressly identified.

The design and functionality described in this application is intendedto be exemplary in nature and is not intended to limit the instantdisclosure in any way. Those having ordinary skill in the art willappreciate that the teachings of the disclosure may be implemented in avariety of suitable forms, including those forms disclosed herein andadditional forms known to those having ordinary skill in the art. Forexample, one skilled in the art will recognize that executableinstructions may be stored on a non-transient, computer-readable storagemedium, such that when executed by one or more processors, causes theone or more processors to implement the method described above.

As used in this application, the terms “component,” “module,” “system”and the like are intended to include a computer-related entity, such asbut not limited to hardware, firmware, a combination of hardware andsoftware, software, or software in execution. For example, a componentmay be, but is not limited to being, a process running on a processor, aprocessor, an object, an executable, a thread of execution, a program,and/or a computer. By way of illustration, both an application runningon a computing device and the computing device can be a component. Oneor more components can reside within a process and/or thread ofexecution and a component may be localized on one computer and/ordistributed between two or more computers. In addition, these componentscan execute from various computer readable media having various datastructures stored thereon. The components may communicate by way oflocal and/or remote processes such as in accordance with a signal havingone or more data packets, such as data from one component interactingwith another component in a local system, distributed system, and/oracross a network such as the Internet with other systems by way of thesignal.

Certain embodiments of this technology are described above withreference to block and flow diagrams of computing devices and methodsand/or computer program products according to example embodiments of thedisclosure. It will be understood that one or more blocks of the blockdiagrams and flow diagrams, and combinations of blocks in the blockdiagrams and flow diagrams, respectively, can be implemented bycomputer-executable program instructions. Likewise, some blocks of theblock diagrams and flow diagrams may not necessarily need to beperformed in the order presented, or may not necessarily need to beperformed at all, according to some embodiments of the disclosure.

These computer-executable program instructions may be loaded onto ageneral-purpose computer, a special-purpose computer, a processor, orother programmable data processing apparatus to produce a particularmachine, such that the instructions that execute on the computer,processor, or other programmable data processing apparatus create meansfor implementing one or more functions specified in the flow diagramblock or blocks. These computer program instructions may also be storedin a computer-readable memory that can direct a computer or otherprogrammable data processing apparatus to function in a particularmanner, such that the instructions stored in the computer-readablememory produce an article of manufacture including instruction meansthat implement one or more functions specified in the flow diagram blockor blocks.

As an example, embodiments of this disclosure may provide for a computerprogram product, comprising a computer-usable medium having acomputer-readable program code or program instructions embodied therein,said computer-readable program code adapted to be executed to implementone or more functions specified in the flow diagram block or blocks. Thecomputer program instructions may also be loaded onto a computer orother programmable data processing apparatus to cause a series ofoperational elements or steps to be performed on the computer or otherprogrammable apparatus to produce a computer-implemented process suchthat the instructions that execute on the computer or other programmableapparatus provide elements or steps for implementing the functionsspecified in the flow diagram block or blocks.

Accordingly, blocks of the block diagrams and flow diagrams supportcombinations of means for performing the specified functions,combinations of elements or steps for performing the specifiedfunctions, and program instruction means for performing the specifiedfunctions. It will also be understood that each block of the blockdiagrams and flow diagrams, and combinations of blocks in the blockdiagrams and flow diagrams, can be implemented by special-purpose,hardware-based computer systems that perform the specified functions,elements or steps, or combinations of special-purpose hardware andcomputer instructions.

While certain embodiments of this disclosure have been described inconnection with what is presently considered to be the most practicaland various embodiments, it is to be understood that this disclosure isnot to be limited to the disclosed embodiments, but on the contrary, isintended to cover various modifications and equivalent arrangementsincluded within the scope of the appended claims. Although specificterms are employed herein, they are used in a generic and descriptivesense only and not for purposes of limitation.

This written description uses examples to disclose certain embodimentsof the technology and also to enable any person skilled in the art topractice certain embodiments of this technology, including making andusing any apparatuses or systems and performing any incorporatedmethods. The patentable scope of certain embodiments of the technologyis defined in the claims, and may include other examples that occur tothose skilled in the art. Such other examples are intended to be withinthe scope of the claims if they have structural elements that do notdiffer from the literal language of the claims, or if they includeequivalent structural elements with insubstantial differences from theliteral language of the claims.

There is much that can be determined about the properties of CT scanneditems (e.g.: dimensions, density, internal configurations, hiddendefects, materials of construction, etc.), however, the comparative CTprocess is unique in that it uses the ability to determine dimensionaland material properties to ensure that a commercial grade item isequivalent to a baseline sample of previously qualified items.

The system, methods, and apparatus disclosed are intended to prove partor component sameness (dimensional and materials). Instead of provingeach item will individually meet the requirements of a specification,comparison CT scanning to a traditionally qualified baseline of alreadyqualified items, confirms and documents likeness of equivalentcommercial grade versions of the same items. After a baseline isestablished, easier to acquire (and less expensive) commercial gradeitems can be scanned, then qualified, based on being like the baselineitems.

The invention claimed is:
 1. A method of qualifying physical componentsusing computed tomography (CT), the method comprising the steps of:obtaining, via a processor, qualified CT data from a CT scanner for atleast one qualified physical component; generating, via the processor,qualification data based on the qualified CT data, where thequalification data defines a qualification envelope; obtaining, via theprocessor, candidate CT data from the CT scanner for a candidatephysical component; generating, via the processor, comparison data basedon the candidate CT data and the qualification data, where thecomparison data indicates whether the candidate CT data is within thequalification envelope defined by the qualification data; andgenerating, via the processor, an acceptance signal if the comparisondata meets acceptance criteria.
 2. The method of claim 1, where theacceptance criteria requires that the entirety of the candidate CT datais within the qualification envelope defined by the qualification data.3. The method of claim 1, where: the qualified CT data comprises aplurality of volumetric pixels (voxels); the qualification datacomprises a plurality of voxels; candidate CT data comprises a pluralityof voxels; and the comparison data comprises a plurality of voxels. 4.The method of claim 3, where each voxel comprises a three-dimensional(3D) location and material information.
 5. The method of claim 4, wherethe at least one qualified physical component comprises a plurality ofcomponents; and where the qualification data comprises a database ofthree-dimensional (3D) location and material information for each voxelof each of the pluralities' components.
 6. The method of claim 5, wherethe material information comprises density information.
 7. The method ofclaim 6, where the material information further compriseseffective-atomic number (Zeff) information.
 8. The method of claim 1,where generating comparison data further comprises the steps of:aligning the voxels of the qualification data for each of the pluralityof components; generating an ordered list of recorded material readingsfrom the plurality of components for each voxel; and defining, via theprocessor, the qualification envelope for each voxel in the qualified CTdata based on the ordered list.
 9. The method of claim 8, where theordered list is ordered based on the materials information.
 10. Themethod of claim 8, where defining the qualification envelope furthercomprises the steps of: establishing a conservatism factor based upon:accuracy of positioning the physical component on CT scanner accuracy ofCT scanner and CT data conservatism assigned to meet qualificationprocess requirements of the candidate physical component end user; andeliminating a subset of the ordered list of recorded material readingsfrom the plurality of components for each voxel based on theconservatism factor.
 11. The method of claim 8, further comprising thesteps of: obtaining at least one datum for the qualified CT data;obtaining at least one datum for the candidate CT data; and aligning theat least one datum for the candidate CT data with the at least one datumfor the qualified CT data for the purpose of comparing dimensional andmaterials properties.
 12. The method of claim 8, further comprising thestep of correcting for physical component placement error.
 13. Themethod of claim 11, where at least one datum for the qualified CT dataand at least one datum for the candidate CT data, are based on a featureof the CT scanner.
 14. The method of claim 13, where a feature of the CTscanner comprises radiopacity to determine material density.
 15. Themethod of claim 11, further comprising the steps of: generating, via theprocessor, at least one datum for the qualified CT data, based on thequalified CT data; generating, via the processor, at least one datum forthe candidate CT data based on candidate CT data; and aligning, via theprocessor, the at least one datum for the candidate CT data with the atleast one datum for the qualified CT data.
 16. The method of claim 15,where generating a datum comprises identifying, via the processor, atleast one edge condition in the CT data, where the edge condition in theCT data is associated with an edge in the physical component.
 17. Themethod of claim 13, where the physical object is positioned in thescanner with a jig.
 18. The method of claim 17, where the jig comprisesthe feature of the CT scanner.
 19. The method of claim 1, whereobtaining qualified CT data and obtaining candidate CT data comprisescanning the at least one qualified physical component and the candidatephysical components with X-rays of multiple energy levels; andcalculating an effective-atomic number (Zeff) for each voxel.
 20. Asystem for qualifying physical components using computed tomography (CT)comprising: a CT scanner, a processor operatively connected to the CTscanner; and non-transient memory operatively connected to theprocessor, the memory comprising instruction which cause the processorto execute a method comprising the steps of: obtaining, via a processor,qualified CT data from a CT scanner for at least one qualified physicalcomponent; generating, via the processor, qualification data based onthe qualified CT data, where the qualification data defines aqualification envelope: obtaining, via the processor, candidate CT datafrom the CT scanner for a candidate physical component; generating, viathe processor, comparison data based on the candidate CT data and thequalification data, where the comparison data indicates whether thecandidate CT data is within the qualification envelope defined by thequalification data; and generating, via the processor, an acceptancesignal if the comparison data meets acceptance criteria.